Patent attributes
An add-on device adapted to be releasably attached to a drug delivery device, the drug delivery device comprising an indicator adapted to display a dose amount during dose setting, and to display the remaining dose amount to be expelled during drug expelling. The add-on device comprises an electronically controlled display adapted to display a set dose amount, a sensor assembly adapted to detect movement of the dose setting member when the add-on device is attached to a drug delivery device, a camera device adapted to capture an image of the indicator, and processor means adapted to (i) control the display dynamically to show the set dose amount based on input from the sensor assembly, and (ii) determine an expelled dose amount based on input from the camera device.